Question

here is a json tree from wikipedia. http://en.wikipedia.org/w/api.php?action=query&titles=japan&prop=categories&format=json

I met a trouble in "pages": { "15573": {. If I will turn the query word, the page number is always changed. How to do a json decode when a child nod is a radom number? Thanks.

{
    "query": {
        "normalized": [
            {
                "from": "japan",
                "to": "Japan"
            }
        ],
        "pages": {
            "15573": {
                "pageid": 15573,
                "ns": 0,
                "title": "Japan",
                "categories": [
                    {
                        "ns": 14,
                        "title": "Category:All articles containing potentially dated statements"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Article Feedback Pilot"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Articles containing Japanese language text"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Articles containing potentially dated statements from 2010"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Articles containing potentially dated statements from January 2011"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Constitutional monarchies"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Countries bordering the Pacific Ocean"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Countries bordering the Philippine Sea"
                    },
                    {
                        "ns": 14,
                        "title": "Category:East Asian countries"
                    },
                    {
                        "ns": 14,
                        "title": "Category:Empires"
                    }
                ]
            }
        }
    },
    "query-continue": {
        "categories": {
            "clcontinue": "15573|Featured articles"
        }
    }
}

Answer 1

You can do this (based on what you want in comment):

$json_array = json_decode($json, true);

foreach($json_array['query']['pages'] as $page)
{
    print_r($page['categories']);
}

I’m assuming you want to access it as array, but you can also do it with the default return value, with little modification of course.